1. Field
Embodiments of the invention relate to digital devices. More specifically, one embodiment of the invention relates to an apparatus and method for delivery content over a network and descrambling the received digital content.
2. General Background
Television is used to deliver entertainment and education to viewers. The source material (audio, video, etc.) is multiplexed into a combined signal which is then used to modulate a carrier. This carrier is commonly known as a channel. A typical channel may carry one analog program, one or two high definition (HD) digital program(s), or perhaps several (e.g. nine) standard definition digital programs.
In a cable system, the modulated channels are carried over a cable. There may also be an in-band or out-of-band feed of a program guide, which indicates what programs are available and the associated tuning information. The number of cable channels is finite and limited by equipment/cable bandwidth. A conventional cable system is illustrated in FIG. 1.
In such a system, the cable operator processes audio/video (A/V) content 14 with conditional access (CA) technology from manufacturer A (system A) using CA encryption equipment 18 compliant with system A at the cable system head-end 22. The encrypted A/V content along with system information (SI) 26 and program specific information (PSI) 27 is multiplexed together and transmitted over the cable system 32 to a user's set-top box (STB) 36. The STB 36 incorporates decrypting CA equipment from system A 40 that decrypts the A/V content. The decrypted A/V content can then be supplied to a television set 44 for viewing by the user.
Similarly, in a terrestrial broadcast or a direct satellite broadcast, however, these channels correspond to wireless signal frequencies. The program is delivered to a receiver having a tuner that recovers the signal from the air and delivers it to a demodulator. The demodulator, in turn, provides video to a display and audio to speakers.
Over time, these above-identified service providers as well as other service providers may use, in whole or in part, publicly accessible networks (e.g., Internet or an Internet Protocol (IP) based network) for downloading content (e.g., video, audio, digital pictures, and other data). Since most digital content is a valuable asset, most content owners want to control access and restrict copies. As a result, content protection schemes that support the transfer of digital content over a public network are needed.